Differ::diff() - Code Metrics - Inspection of "readme" - p6naveen/project-1 - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 95acd7...e70d94 )

by Naveen

created 2016-02-13 10:58 UTC

Differ::diff() F

↳ Parent: Project

Complexity

Conditions	19
Paths	2400

Size

Total Lines	67
Code Lines	40

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
c	1
b	0
f	0
dl	0
loc	67
rs	2.7051
cc	19
eloc	40
nc	2400
nop	3

How to fix Long Method Complexity

<?php
/*
 * This file is part of the Diff package.
 *
 * (c) Sebastian Bergmann <[email protected]>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace SebastianBergmann\Diff;

use SebastianBergmann\Diff\LCS\LongestCommonSubsequence;
use SebastianBergmann\Diff\LCS\TimeEfficientImplementation;
use SebastianBergmann\Diff\LCS\MemoryEfficientImplementation;

/**
 * Diff implementation.
 */
class Differ
{
    /**
     * @var string
     */
    private $header;

    /**
     * @var bool
     */
    private $showNonDiffLines;

    /**
     * @param string $header
     */
    public function __construct($header = "--- Original\n+++ New\n", $showNonDiffLines = true)
    {
        $this->header           = $header;
        $this->showNonDiffLines = $showNonDiffLines;
    }

    /**
     * Returns the diff between two arrays or strings as string.
     *
     * @param array|string             $from
     * @param array|string             $to
     * @param LongestCommonSubsequence $lcs
     *
     * @return string
     */
    public function diff($from, $to, LongestCommonSubsequence $lcs = null)
    {
        if (!is_array($from) && !is_string($from)) {
            $from = (string) $from;
        }

        if (!is_array($to) && !is_string($to)) {
            $to = (string) $to;
        }

        $buffer = $this->header;
        $diff   = $this->diffToArray($from, $to, $lcs);

        $inOld = false;
        $i     = 0;
        $old   = array();

        foreach ($diff as $line) {
            if ($line[1] ===  0 /* OLD */) {
                if ($inOld === false) {
                    $inOld = $i;
                }
            } elseif ($inOld !== false) {
                if (($i - $inOld) > 5) {
                    $old[$inOld] = $i - 1;
                }

                $inOld = false;
            }

            ++$i;
        }

        $start = isset($old[0]) ? $old[0] : 0;
        $end   = count($diff);

        if ($tmp = array_search($end, $old)) {
            $end = $tmp;
        }

        $newChunk = true;

        for ($i = $start; $i < $end; $i++) {
            if (isset($old[$i])) {
                $buffer  .= "\n";
                $newChunk = true;
                $i        = $old[$i];
            }

            if ($newChunk) {
                if ($this->showNonDiffLines === true) {
                    $buffer .= "@@ @@\n";
                }
                $newChunk = false;
            }

            if ($diff[$i][1] === 1 /* ADDED */) {
                $buffer .= '+' . $diff[$i][0] . "\n";
            } elseif ($diff[$i][1] === 2 /* REMOVED */) {
                $buffer .= '-' . $diff[$i][0] . "\n";
            } elseif ($this->showNonDiffLines === true) {
                $buffer .= ' ' . $diff[$i][0] . "\n";
            }
        }

        return $buffer;
    }

    /**
     * Returns the diff between two arrays or strings as array.
     *
     * Each array element contains two elements:
     *   - [0] => string $token
     *   - [1] => 2|1|0
     *
     * - 2: REMOVED: $token was removed from $from
     * - 1: ADDED: $token was added to $from
     * - 0: OLD: $token is not changed in $to
     *
     * @param array|string             $from
     * @param array|string             $to
     * @param LongestCommonSubsequence $lcs
     *
     * @return array
     */
    public function diffToArray($from, $to, LongestCommonSubsequence $lcs = null)
    {
        preg_match_all('(\r\n|\r|\n)', $from, $fromMatches);
        preg_match_all('(\r\n|\r|\n)', $to, $toMatches);

        if (is_string($from)) {
            $from = preg_split('(\r\n|\r|\n)', $from);
        }

        if (is_string($to)) {
            $to = preg_split('(\r\n|\r|\n)', $to);
        }

        $start      = array();
        $end        = array();
        $fromLength = count($from);
        $toLength   = count($to);
        $length     = min($fromLength, $toLength);

        for ($i = 0; $i < $length; ++$i) {
            if ($from[$i] === $to[$i]) {
                $start[] = $from[$i];
                unset($from[$i], $to[$i]);
            } else {
                break;
            }
        }

        $length -= $i;

        for ($i = 1; $i < $length; ++$i) {
            if ($from[$fromLength - $i] === $to[$toLength - $i]) {
                array_unshift($end, $from[$fromLength - $i]);
                unset($from[$fromLength - $i], $to[$toLength - $i]);
            } else {
                break;
            }
        }

        if ($lcs === null) {
            $lcs = $this->selectLcsImplementation($from, $to);
        }

        $common = $lcs->calculate(array_values($from), array_values($to));
        $diff   = array();

        if (isset($fromMatches[0]) && $toMatches[0] &&
            count($fromMatches[0]) === count($toMatches[0]) &&
            $fromMatches[0] !== $toMatches[0]) {
            $diff[] = array(
              '#Warning: Strings contain different line endings!', 0
            );
        }

        foreach ($start as $token) {
            $diff[] = array($token, 0 /* OLD */);
        }

        reset($from);
        reset($to);

        foreach ($common as $token) {
            while ((($fromToken = reset($from)) !== $token)) {
                $diff[] = array(array_shift($from), 2 /* REMOVED */);
            }

            while ((($toToken = reset($to)) !== $token)) {
                $diff[] = array(array_shift($to), 1 /* ADDED */);
            }

            $diff[] = array($token, 0 /* OLD */);

            array_shift($from);
            array_shift($to);
        }

        while (($token = array_shift($from)) !== null) {
            $diff[] = array($token, 2 /* REMOVED */);
        }

        while (($token = array_shift($to)) !== null) {
            $diff[] = array($token, 1 /* ADDED */);
        }

        foreach ($end as $token) {
            $diff[] = array($token, 0 /* OLD */);
        }

        return $diff;
    }

    /**
     * @param array $from
     * @param array $to
     *
     * @return LongestCommonSubsequence
     */
    private function selectLcsImplementation(array $from, array $to)
    {
        // We do not want to use the time-efficient implementation if its memory
        // footprint will probably exceed this value. Note that the footprint
        // calculation is only an estimation for the matrix and the LCS method
        // will typically allocate a bit more memory than this.
        $memoryLimit = 100 * 1024 * 1024;

        if ($this->calculateEstimatedFootprint($from, $to) > $memoryLimit) {
            return new MemoryEfficientImplementation;
        }

        return new TimeEfficientImplementation;
    }

    /**
     * Calculates the estimated memory footprint for the DP-based method.
     *
     * @param array $from
     * @param array $to
     *
     * @return int
     */
    private function calculateEstimatedFootprint(array $from, array $to)
    {
        $itemSize = PHP_INT_SIZE == 4 ? 76 : 144;

        return $itemSize * pow(min(count($from), count($to)), 2);
    }
}


1			<?php
2			/*
3			* This file is part of the Diff package.
4			*
5			* (c) Sebastian Bergmann <[email protected]>
6			*
7			* For the full copyright and license information, please view the LICENSE
8			* file that was distributed with this source code.
9			*/
10
11			namespace SebastianBergmann\Diff;
12
13			use SebastianBergmann\Diff\LCS\LongestCommonSubsequence;
14			use SebastianBergmann\Diff\LCS\TimeEfficientImplementation;
15			use SebastianBergmann\Diff\LCS\MemoryEfficientImplementation;
16
17			/**
18			* Diff implementation.
19			*/
20			class Differ
21			{
22			/**
23			* @var string
24			*/
25			private $header;
26
27			/**
28			* @var bool
29			*/
30			private $showNonDiffLines;
31
32			/**
33			* @param string $header
34			*/
35			public function __construct($header = "--- Original\n+++ New\n", $showNonDiffLines = true)
36			{
37			$this->header = $header;
38			$this->showNonDiffLines = $showNonDiffLines;
39			}
40
41			/**
42			* Returns the diff between two arrays or strings as string.
43			*
44			* @param array\|string $from
45			* @param array\|string $to
46			* @param LongestCommonSubsequence $lcs
47			*
48			* @return string
49			*/
50			public function diff($from, $to, LongestCommonSubsequence $lcs = null)
51			{
52			if (!is_array($from) && !is_string($from)) {
53			$from = (string) $from;
54			}
55
56			if (!is_array($to) && !is_string($to)) {
57			$to = (string) $to;
58			}
59
60			$buffer = $this->header;
61			$diff = $this->diffToArray($from, $to, $lcs);
62
63			$inOld = false;
64			$i = 0;
65			$old = array();
66
67			foreach ($diff as $line) {
68			if ($line[1] === 0 /* OLD */) {
69			if ($inOld === false) {
70			$inOld = $i;
71			}
72			} elseif ($inOld !== false) {
73			if (($i - $inOld) > 5) {
74			$old[$inOld] = $i - 1;
75			}
76
77			$inOld = false;
78			}
79
80			++$i;
81			}
82
83			$start = isset($old[0]) ? $old[0] : 0;
84			$end = count($diff);
85
86			if ($tmp = array_search($end, $old)) {
87			$end = $tmp;
88			}
89
90			$newChunk = true;
91
92			for ($i = $start; $i < $end; $i++) {
93			if (isset($old[$i])) {
94			$buffer .= "\n";
95			$newChunk = true;
96			$i = $old[$i];
97			}
98
99			if ($newChunk) {
100			if ($this->showNonDiffLines === true) {
101			$buffer .= "@@ @@\n";
102			}
103			$newChunk = false;
104			}
105
106			if ($diff[$i][1] === 1 /* ADDED */) {
107			$buffer .= '+' . $diff[$i][0] . "\n";
108			} elseif ($diff[$i][1] === 2 /* REMOVED */) {
109			$buffer .= '-' . $diff[$i][0] . "\n";
110			} elseif ($this->showNonDiffLines === true) {
111			$buffer .= ' ' . $diff[$i][0] . "\n";
112			}
113			}
114
115			return $buffer;
116			}
117
118			/**
119			* Returns the diff between two arrays or strings as array.
120			*
121			* Each array element contains two elements:
122			* - [0] => string $token
123			* - [1] => 2\|1\|0
124			*
125			* - 2: REMOVED: $token was removed from $from
126			* - 1: ADDED: $token was added to $from
127			* - 0: OLD: $token is not changed in $to
128			*
129			* @param array\|string $from
130			* @param array\|string $to
131			* @param LongestCommonSubsequence $lcs
132			*
133			* @return array
134			*/
135			public function diffToArray($from, $to, LongestCommonSubsequence $lcs = null)
136			{
137			preg_match_all('(\r\n\|\r\|\n)', $from, $fromMatches);
138			preg_match_all('(\r\n\|\r\|\n)', $to, $toMatches);
139
140			if (is_string($from)) {
141			$from = preg_split('(\r\n\|\r\|\n)', $from);
142			}
143
144			if (is_string($to)) {
145			$to = preg_split('(\r\n\|\r\|\n)', $to);
146			}
147
148			$start = array();
149			$end = array();
150			$fromLength = count($from);
151			$toLength = count($to);
152			$length = min($fromLength, $toLength);
153
154			for ($i = 0; $i < $length; ++$i) {
155			if ($from[$i] === $to[$i]) {
156			$start[] = $from[$i];
157			unset($from[$i], $to[$i]);
158			} else {
159			break;
160			}
161			}
162
163			$length -= $i;
164
165			for ($i = 1; $i < $length; ++$i) {
166			if ($from[$fromLength - $i] === $to[$toLength - $i]) {
167			array_unshift($end, $from[$fromLength - $i]);
168			unset($from[$fromLength - $i], $to[$toLength - $i]);
169			} else {
170			break;
171			}
172			}
173
174			if ($lcs === null) {
175			$lcs = $this->selectLcsImplementation($from, $to);
176			}
177
178			$common = $lcs->calculate(array_values($from), array_values($to));
179			$diff = array();
180
181			if (isset($fromMatches[0]) && $toMatches[0] &&
182			count($fromMatches[0]) === count($toMatches[0]) &&
183			$fromMatches[0] !== $toMatches[0]) {
184			$diff[] = array(
185			'#Warning: Strings contain different line endings!', 0
186			);
187			}
188
189			foreach ($start as $token) {
190			$diff[] = array($token, 0 /* OLD */);
191			}
192
193			reset($from);
194			reset($to);
195
196			foreach ($common as $token) {
197			while ((($fromToken = reset($from)) !== $token)) {
198			$diff[] = array(array_shift($from), 2 /* REMOVED */);
199			}
200
201			while ((($toToken = reset($to)) !== $token)) {
202			$diff[] = array(array_shift($to), 1 /* ADDED */);
203			}
204
205			$diff[] = array($token, 0 /* OLD */);
206
207			array_shift($from);
208			array_shift($to);
209			}
210
211			while (($token = array_shift($from)) !== null) {
212			$diff[] = array($token, 2 /* REMOVED */);
213			}
214
215			while (($token = array_shift($to)) !== null) {
216			$diff[] = array($token, 1 /* ADDED */);
217			}
218
219			foreach ($end as $token) {
220			$diff[] = array($token, 0 /* OLD */);
221			}
222
223			return $diff;
224			}
225
226			/**
227			* @param array $from
228			* @param array $to
229			*
230			* @return LongestCommonSubsequence
231			*/
232			private function selectLcsImplementation(array $from, array $to)
233			{
234			// We do not want to use the time-efficient implementation if its memory
235			// footprint will probably exceed this value. Note that the footprint
236			// calculation is only an estimation for the matrix and the LCS method
237			// will typically allocate a bit more memory than this.
238			$memoryLimit = 100 * 1024 * 1024;
239
240			if ($this->calculateEstimatedFootprint($from, $to) > $memoryLimit) {
241			return new MemoryEfficientImplementation;
242			}
243
244			return new TimeEfficientImplementation;
245			}
246
247			/**
248			* Calculates the estimated memory footprint for the DP-based method.
249			*
250			* @param array $from
251			* @param array $to
252			*
253			* @return int
254			*/
255			private function calculateEstimatedFootprint(array $from, array $to)
256			{
257			$itemSize = PHP_INT_SIZE == 4 ? 76 : 144;
258
259			return $itemSize * pow(min(count($from), count($to)), 2);
260			}
261			}
262

p6naveen / project-1

Push — master ( 95acd7...e70d94 )

Differ::diff() F

Complexity

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Duplication

Importance

How to fix Long Method Complexity

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